5+ Year Member
Mar 3, 2010
Medical Student
I just completed my BR organic books and they are as good as everyone says, but I am wondering to what extent are specific reactions expected to be known offhand (i.e. baeyar-villager, anti-markinov addition)?

Do most orgo passages provide details to the specifics and expect us to know patterns of how things add across double bonds or act in acidic solution (i'm guessing it is like this?)

Any insights from people who've tested recently are greatly appreciated


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10+ Year Member
May 22, 2008
Deep in the heart of Texas
Attending Physician
In my experience there weren't too many questions on specific details of mechanisms. You would need to know, for example, whether a particular reaction was Markovnikov or anti-Markovnikov, but you likely wouldn't need to know much more beyond that. That said, I DID encounter questions that required detailed knowledge of mechanisms, but they weren't common. Unless you have plenty of time to study, I would worry more about the general reactants/products of a reaction rather than the gritty details of the mechanisms. That tends to be more high-yield.

In short, I think your idea of the passages and questions is accurate.


10+ Year Member
7+ Year Member
Dec 29, 2008
Atlanta, Georgia
The most important organic mechanisms for the MCAT are the ones you see all the time in biochemistry, things like addition-elimination among carboxylic acid derivatives (including being able to apply the addition-elimination form to phosphoryl transfer), aldol condensation, dehydration of alcohols, and acetal formation. Not only does this make sense in terms of the human biology general science premed curriculum (to de-emphasize the chemical engineering side of organic versus the biological), but also the understanding of organic mechanisms is frequently tested in passages with a biochemistry theme. Inclusion of radioisotopes in the presented material is often used to test the understanding of the mechanisms, for example, which oxygen leaves the substrate in the dehydration of glycerol and three fatty acids, the one on the glycerol hydroxyl or one of the carboxylate oxygens? That kind of thing.

The other big set of mechanisms you need to know are the fundamental model mechanisms such as SN2 substitution, free radical addition, or electrophilic aromatic addition, or even things like 1,2 versus 1,4 addition to butadiene. Have a good example in mind for Markovnikov addition, carbocation rearrangement, inversion of configuration, racemization, Zaitsev's rule, Hammond's postulate and a few other things.

There are obscure mind-benders the MCAT likes to put over now and again like Hoffman rearrangement or something from the Diels-Alder side of things no pre-med's ever seen before. If it's something like that, they want to see if you can hang on and answer the questions, so it won't be about prior knowledge.

Don't forget organic redox.
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